1. Field of the Invention
The present invention relates to semiconductor manufacturing and, more particularly, to apparatuses and methods for use in processing a substrate.
2. Description of the Related Art.
In the fabrication of semiconductor devices, there is a need to perform substrate (e.g., semiconductor wafer) cleaning. For example, the process of manufacturing electronic devices on semiconductor wafers involves a complex process of depositing and removing a number of layers. Typically, patterning of layer materials includes the application of an organic photoresist onto the semiconductor wafer. After plasma chemistry etches a target material, the semiconductor wafer needs to be cleaned to remove the organic photoresist. If the organic photoresist is not removed, the organic photoresist will contaminate the semiconductor wafer resulting in damage to the electronic devices on the semiconductor wafer. In addition, after a chemical mechanical polishing (CMP) operation, residual particles or films are left on the surface of the semiconductor wafer. Similarly, these residual particles or films may cause defects such as scratches on the wafer surface which may cause devices on the wafer to become inoperable. To avoid damaging the devices, the wafer also needs to be cleaned after the CMP operation. As such, cleaning operations define a very critical step that is repeated many times throughout the process of fabricating semiconductor devices.
FIG. 1 is a simplified side view of a conventional system used to clean semiconductor wafers. The cleaning system includes two brushes 110 configured to receive semiconductor wafer 112 between the brushes. Foam 114 is supplied to the surface of semiconductor wafer 112 and brushes 110 rotate to scrub the surface of the semiconductor wafer to remove particles and film. The problem with applying foam 114 in an open environment is that the foam haphazardly grows around brushes 110 and cannot be directed to a particular surface area of semiconductor wafer 112. In other words, the flow of foam 114 is difficult to control when applied in an open environment. Furthermore, different properties of foam 114 result in different cleaning capabilities, and the properties of foam 114 are also difficult to control when applied in the open environment. The application of foam 114 in the open environment is also wasteful as a large quantity of the foam is needed to insure a uniform distribution across the surface of semiconductor wafer 112.
In view of the foregoing, there is a need to conserve the use of foam and to control the physical properties and flow of foam when applied on the surface of the semiconductor wafer.